Figure 5-1. Fault 1, Open Thermocouple - Emerson Oxymitter 5000 Instruction Manual

Oxymitter 5000
DIAGNOSTIC
ALARMS
CALIBRATION RECOMMENDED
TEST
POINTS
INC INC
HIGH LOW
GAS GAS
DEC DEC

Figure 5-1. Fault 1, Open Thermocouple

Rosemount Analytical Inc. A Division of Emerson Process Management
HEATER T/C
HEATER SW2
O2 CELL
CALIBRATION
J1
O2 CELL mV +
TP1
O2 CELL mv -
TP2
HEATER T/C +
TP3
HEATER T/C -
TP4
CAL
TEST GAS +
TP5
PROCESS -
TP6
% O2
28550014
Instruction Manual
a. Fault 1, Open Thermocouple
The HEATER T/C LED flashes once,
pauses for three seconds, and repeats (Fig-
ure 5-1).
1. Check connector J1. Ensure the con-
nector is properly seated.
2. Using a multimeter, measure TP3+ to
TP4-. If the reading is 1.2 VDC ±0.1
VDC, the thermocouple is open.
3. Remove power. Disconnect J1. Meas-
ure continuity across the red and yel-
low thermocouple leads.
4. The measurement should read ap-
proximately 1 ohm.
5. If the thermocouple is open, see para-
graph 4-7, Heater Strut Replacement.
IB-106-350 Rev. 1.2
April 2001
Troubleshooting 5-3
5